North Korea threatened on Thursday to prepare for a long-term fight with the United States and restart nuclear testing it had paused during peace talks with former President Donald Trump’s administration.

During a meeting of the Central Committee of North Korea’s sole political party, the Workers’ Party of Korea (WPK), North Korean leader Kim Jong Un criticized the U.S. for condemning a series of recent ballistic missile tests, which he described as a “legitimate exercise of sovereignty.” In remarks first reported by North Korean state media and shared by KCNA Watch, the ruling communist party discussed ways to increasingly orient its military against the U.S., including restarting the nuclear weapons tests.

The communist party committee said North Korea would need new ways to counter the U.S. because of continued U.S. military drills with South Korea and because the U.S. “viciously slurred our state and committed the foolish act of taking over 20 independent sanctions measures.” The committee said President Joe Biden’s administration “especially . . . persists in maneuvers to deprive the [Democratic People’s Republic of Korea] of its right to self-defence.”